Lamp



' Sept. 2,1947. P. J, WALSH 2,426,907

LAMP

Filed Jan. 29, 194,6 2 Sheets-Shee t' 1 I v nvwwrok F i PATRICK J. WALSHTTORWE Y 2 Sheets-Sheet 2 'P. J. WALSH Sept. 2, 1947.

- LAMP INVENTDR PATRICK J. WALSH TTORNEY Patented Sept. 2, 1947 UNITEDSTATES PATENT OFFICE LAMP 7 Patrick 2!. Welsh, New York,'N. Y.Application January 29, 1946, :Serial No.-644,030

fi-(llaims. 1 This invention is a lamp wherein the intensity of theillumination therefrom may be varied at the will of-the operator.

The lamp of this invention preferably embodies a pluralityofrincandescent filament bulbs mounted on an appropriate standard orcolumn, carried by a base which encloses a receptacle or vesselcontaining a liquid adapted to pass electrical-current, but withvariablerresistance to such passage depending-upon the spacing-of theelectrodes between which the current is fed through the liquid. Withinthe base of the lamp is a switching device electrically connected to theseveral bulbs and thlOllgh the -manipulation of this current switchingdevice :said lamps may be energized in succession, so that one -or moreof them may be illuminated with normal maximum brilliancy. Associatedwith said switching device is also amanually operablemember to which isconnected a movable arm adapted to be shift- .edfrom a point above thesurface of the liquid in the vessel to various depths within the liquidand into engagement with a .iixed contact .near the base of the vessel.The movable arm and fixed contact are included in a circuit shunting theswitching device .and including one of the bulbs so that, when theswitching device is in position to extinguish all of the bulbs, themovable arm may be manipulated to illuminate one of them and control theintensity of light therefrom, according to the relative positionsbetween the movable arm and the submerged fixed contact. With thisarrangement one or more of the bulbs may be lit when relatively brightillumination is desired or all of these bulbs may be extinguished andone of them energized with such degree of dimness as may be desired-bythe operator.

Features of the invention, other than thoseiadverted to, will beapparent from the hereinafter detailed description and claims, when readin conjunction with the accompanyingdrawings.

The accompanying drawings illustrate one practical embodiment of theinvention, but the construction therein shown is to be. understood .asillustrative, only, and not as definingthe embodiments of the invention.a

Figure .1 is a vertical section through a lamp embodying the presentinvention, the same being shown as a table lamp.

Figure 2 is a section ,on the line 2-2 of Figure 1.

Figure 3 isa-fragmentalsection on the line 33 .of Figure 2.

Referring to the drawings, indicates a -tu 'bular column on the upperend of which is mounteda head 2 supportinga plurality of lamp socketsI3, lland 5. These sockets are adapted to receive incandescent bulbsl'3a, 4aand 5a, respectively. Three of .thesebulbs are shown but more orless may be used without departingfrom the invention.

The lower-end of the column is threaded to be screwed upon and supportedby a threaded boss 6 on the cover 1- of a receptacle 8. This receptacleis preferably made of plastic material or of some other-dielectricsubstance. The cover is hinged at one side, as indicated at 9, andhas acatch at its opposite side so that it can be normally secured in closedposition.

The bottom of the receptacle is extended as .shOWn at .H "toiorma baseforthe lamp and to this base asuitable-s'hell L2 is attached by means ofscrews 1'3- This shell may be of any appropriate shape and its function.is to enclose the receptacle, switching device, etc and form an outerhousing-of pleasing and artistic appearance.

Withinthe base of the receptacle '8 is positioned a conductive platell,.preferably of copper, and :at one point of the periphery of thisplate, it is turned up to provide a contact I positioned within thereceptacle and having on the exteriorof the receptacle a binding post towhich is affixed a terminal or terminal connection 16.

The receptacle 8 may be of anydesired shape, but for the purpose ofillustration, I have shown itas provided near. its top with oppositelyprojecting lateral extensions I1. One of these extensions serves as asupport for a spindle is which passes through the opposite walls thereof(see Figure 2) with a, nut-l9 at one end and at its other end a slip'connection 20 by means of which it may be sprung into engagement with ashank 21 of amanually operable knob '22 positioned exteriorly of theshell [2. A gland 23 is associated with the spindle l8 so .as topreclude leakage of liquidIL adapted to be contained within thereceptacle.

Attached-"to the spindle. l8 within the extension H is an arm 24 and aninsulating bushin 25 is interposed between thearm and the spindle toinsulate the latter .from the former. ZBy manipulation of the knob 22,the arm .24 may be swung from the full line position of Figure 1,wherein it. is shown above the surface of the liquid L, downwardly intoengagement with the contact I5 which is submerged insaid liquid.

-Embracing the spindle 118 on the exterior of the receptacle 8 is acurrent switching device. This current switching device embodies aninsulating block 26, secured in fixed position and on the outer surfaceof which are mounted three fixed contacts 21, 28 and 29. With thesecontacts a movable contact or wiper 30 cooperates. This wiper is mountedon an arm 3!, keyed to a sleeve 32, embracing the spindle [8 which hassquared or dog connection with the shank 33 of a knob 34 positionedexteriorly of the shell, directly back of the knob 22. A light spring 35impels the wiper in the direction of the face of theblock of insulation26 on which the contacts 21, 28 and 29 I are positioned. By rotating theknob 34 the wiper 30 may be caused to engage the contacts 21, 28

energized.

Current is fed from a conventional plug 36, through an opening into theinterior of the shell, where the two wires 31 and 38 thereof separate.The wire 31 is connected to the terminal 16 and passes therefrom to thehub 3| of the movable contact 30. The other wire 38 passes upwardlywithin the shell and through an opening 39 near the base of the colunm linto the interior of the column and thence upwardly through the columnto the head 2 within which it is connected to one terminal of each ofthe lamp sockets 3, 4 and 5. From the other terminal of the socket 3 awire 40 leads back through the column to the contact 29 of the switchblock 26. Similarly Wires 4| and 42 lead from the other terminals of thesockets 4 and to the contacts 28 and 21, respectively. A wire 43 isconnected to the wire 4| between the socket 4 and the contact 28 andleads from this wire 4| to the arm 24. This wire 43, together with thearm 24, liquid L and contact l5, collectively from a shunt circuitshunting the current switching device for the several bulbs.

Under normal conditions the arm 24 is in the position shown in Figure 1wherein it lies wholly above the surface of the liquid L. Likewise themovable contact 30 is .in the position shown in this figure so that allcircuits to the'bulbs are dead. When it is desired to turn on the bulbswithout dimming, the knob 34 is rotated in a clockwise direction asviewed in Figures 1 and 3 to move the contact 30 into engagementwith'thecontact 21. This completes the circuit through the bulb 5a and it willglow with maximum intensity. If the rotation of the knob is continued,the contact 30 will next engage with the contact 28 to turn on the bulb4a and continued rotation of the knob will engage the contact 30 alsowith the contact 29, so that all three bulbs will glow brightly. Th'useither one, two or three lamps may be turned on at the will of theoperator. r 3

However, should a dim light be desired,.the movable contact 30 may bereturned to the position in Figure 1 to extinguish all of the bulbs and,while it remains in this position, theknob 22 may be rotated in acounterclockwise direction to correspondingly swing the arm 24 so thatits end is caused to enter into the liquid L. As soon as this occurs,current will pass fromthe arm 24 through the liquid to the conductingplate l4, but with a resistance inversely to the distance between theend of the arm 24 and the plate [4.

In other, words, when just the end of the arm dipsinto the liquid, thecurrent will, flow to the bulb 4a with maximum resistance in the lineand consequently the lamp will glow dimly. The deeper the arm isdepressed into the liquid, the closer it will approach to the contact [5and its and 29 in succession, so that the electrical circuits next to bedescribed may be accumulatively plate l4 and the resistance will becorrespondingly lessened, so that the bulb 4a will glow more brightly.If the arm is brought into the dotted line position of Figure 1, whereinit actually engages the contact I5, there will be no interposed 'liquidresistance and consequently the bulb 4a will glow with its maximumintensity. Thus by manipulating the knob 22, the operator can dim thebulb 4a as desired.

This arrangement makes the lamp particularly useful either to give fullillumination or as a night light where just enough light is required topermit one to see his way around.

Any appropriate liquid L may be used in the receptacle 8 and forconvenience in replenishing this liquid, the cover 1 is provided with anupstanding filling tube 44 which extends to and terminates in anaperture in the shell. The open end of this filling tube is closed by acap 45 having a. spring hinge 46 which normally holds it shut, but itmay be manually opened when desired to permit liquid to be poured intothe vessel. This spring closure also serves as a safety valve in theevent that evaporation of the liquid L occurs at such a rate as to buildup pressure in the vessel. This will not of course ordinarily occur, butmight conceivably happen if the owner of the lamp should remove one ofthe bulbs and improperly use that socket to connect other elec tricalappliances or a plurality of other lamps, as persons sometimes do.

If at any time access is desired to the switchin mechanism within theshell, this may be readily had by removing the screws I3 to release theshell. The shank 21 of the knob 22 is then withdrawn from theball end ofthe spindle i8 and both knobs may then be withdrawn to free the shell.The shell may then be raised above the top of the re ceptacle 8 touncover the switching mechanism. At that time the cover I of thereceptacle may be opened for access into the interior of the latter. Theconnection between the shank 2i and the spindle l8 may vary, but, forthe purpose of illustration, the spindle is shown as having a ball endimmediately adjacent which the spindle is circumferentially toothed,while the shank 2! has a socket with an internal annular bead and thewall of the shank is longitudinally slit so that the shank may be sprungover the ball end to move the bead apast the ball and thus secure theparts together. Between the bead and the free end of the shank are teethcorresponding to the teeth on the spindle and serving to interengagetherewith to lock these parts for simultaneous rotation.

The invention has been shown in the accompanying drawings as associatedwith a table lamp, although in practice it may be incorporated with in afloor lamp or in any other conventional form of lighting device.

The foregoing detailed description sets forth the invention in itspreferred practical form and the invention is to be understood as fullycommensurate with the appended claims.

Having thus fully described the invention, what I claim as new anddesire to secure by Letters Patent is:

l. A lamp comprising a receptacle adapted to contain an electricalresistance liquid, 9. column supporting at least one incandescent lampbulb, an electrical circuit including said lamp bulb and also includinga manually operable switch through which current may be fed directly tothe lamp bulb, a shunt circuit connected across said switch andincluding a fixed contact submerged in the liquid in the receptacle, anda movable contact adjustable through said liquid toward and away fromsaid submerged fixed contact, and means for manually adjusting saidmovable contact to interpose in the shunt circuit the resistance of moreor less of the liquid contained in the receptacle at the will of theoperator to vary the intensity of the bulb thus energized.

2. A lamp comprising a base provided with a receptacle adapted tocontain a resistance liquid, a column extending from the base andsupporting at least one lamp bulb, an electric circuit extending intothe base and upwardly through the column to the lamp bulb and including,within the base, a manually operable switch to directly control the feedof current to the lamp bulb, a shunt circuit connected across the switchwith one terminal of the circuit submerged in the resistance liquid andthe other terminal of the circuit connected to an arm pivotallysupported above the surface of the resistance liquid, and manuallyoperable means for causing said arm to dip into the resistance liquidfor the purpose of completing the shunt circuit through said liquid tothe bulb, the length of the path of current through the liquiddetermining the intensity of the bulb when thus illuminated.

3. A lamp comprising a base provided with a receptacle adapted tocontain a resistance liquid, a column extending from the base andsupporting a plurality of lamp bulbs, an electrical circuit leading intothe base and having a common feed wire extending through the base andthrough the column to one terminal of each of the several lamp bulbs insuccession, a switch within the base comprising fixed and movablecontacts, the fixed contacts being individually connected to the severalbulbs and the movable contact being con-. nected to the common return ofsuch circuit and the movable contact being manually movable to engagesaid fixed contacts accumulatively and in succession, in combinationwith a shunt circuit around the switch and including one of the bulbs,said shunt circuit having normally spaced terminals, one of which issubmerged in the liquid in the receptacle and the other of which is inthe form of an arm manually movable from a point above the surface ofsuch liquid downwardly through the liquid and into contact with theother terminal at the will of the operator.

4. A lamp comprisin a base provided with a receptacle adapted to containa resistance liquid, a column extending from the base and supporting aplurality of lamp bulbs, an electrical circuit leading into the base andhaving a common feed wire extending through the base and through thecolumn to one terminal of each of the several lamp bulbs in succession,a switch within the base comprising fixed and movable contacts, thefixed contacts being individually connected to the several bulbs and themovable contact being connected to the common return of such circuit,and

the movable contact being manually movable to engage said fixed contactsaccumulatively and in succession, in combination with a shunt circuitaround the switch and including one of the bulbs, said shunt circuithaving normally spaced terminals, one of which comprises a conductiveplate at the bottom of the receptacle and is submerged in the liquid inthe receptacle and the other of which is in the form of an arm manuallymovable from a point above the surface of such liquid downwardly throughthe liquid and into contact with the other terminal at the will of theoperator.

5. A lamp comprising a receptacle adapted to contain an electricalresistance liquid, a column supporting at least one incandescent lampbulb, an electrical circuit including said lamp bulb and also includinga manually operable switch through which current may be fed directly tothe lamp bulb, a shunt circuit connected across said switch andincluding a fixed contact submerged in the liquid in the receptacle, anda movable contact adjustable through said liquid toward and away fromsaid submerged fixed contact, and means for manually adjusting saidmovable contact to interpose in the shunt circuit the resistance of moreor less of the liquid contained in the receptacle at the will of theoperator to vary the intensity of the bulb thus energized, saidreceptacle having a filler tube provided with a spring pressed closureadapted to open and relieve gaseous pressure if such becomes present inthe receptacle.

6. A lamp comprising a base provided with a receptacle adapted tocontain a resistance liquid, a column extending from the base andsupporting a plurality of lamp bulbs, an electrical circuit leading intothe base and havin a common feed wire extending through the base andthrough the column to one terminal of each of the several lamp bulbs insuccession, a switch Within the base comprising fixed and movablecontacts, the fixed contacts being individually connected to the severalbulbs and the movable contact being connected to the common return ofsuch circuit and the movable contact being manually movable to engagesaid fixed contacts accumulatively and in succession, in combinationwith a shunt circuit around the switch and including one of the bulbs,said shunt circuit having normally spaced terminals, one of which issubmerged in the liquid in the receptacle and the other of which is inthe form of an arm manually movable from a point above the surface ofsuch liquid downwardly through the liquid and into contact with theother terminal at the will of the operator, said receptacle having afiller tube provided with a spring pressed closure adapted to open andrelieve gaseous pressure if such becomes present in the receptacle.

PATRICK J. WALSH.

